3-anilino-5-methyl-5-(4-phenoxyphenyl)-1,3-oxazolidine-2,4-dione;famoxadone (ISO)

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

fish life cycle toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

08/21/1997 - 01/15/1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EPA OPP 72-4 (Fish Early Life-Stage and Aquatic Invertebrate Life-Cycle Studies)

Version / remarks:

1988

GLP compliance:

yes

Specific details on test material used for the study:

Purity: 97.8%
Batch: DPX-JE874-221

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 3.0, 6.3, 13 , 25 and 50 µg/L
- Sampling method: Analytical determination was performed with samples collected from each replicate test vessel on days 0, 7, 14, 21, 28, 35, and 36. Duplicate samples were collected and stored for possible future analysis. Pretest samples concentrations collected from were a single replicate of the low, middle, and high concentrations one day before the start of the test. The secondary stock solution was also sampled at these times. Fifty-mL samples collected from mid-depth of each replicate test vessel were analyzed. All samples were stored in amber glass bottles containing 20 mL of hexane (Burdick & Jackson, lot# BM551) and approximately 16 drops of 0.1N hydrochloric acid (VWR Scientific, lot# 9707076).

The bottles were gently shaken and transferred The bottles were rinsed with 5 mL of hexane which was then added to the separatory funnel. The funnels were shaken for approximately 3 minutes, allowed to settle for approximately 2 minutes, and the hexane layer was collected into 200 mL TurboVap tubes. The samples were evaporated to dryness at approximately 40°C under a stream of nitrogen. Each sample was then reconstituted with 2 mL of a 50/50 (v/v) acetonitrile (Burdick & Jackson, lot# BL900)/water (Burdick & Jackson, lot# BP535) solution and sonicated for approximately 2 minutes. An aliquot of each sample was transferred to an amber autosampler vial for analysis.
- Sample storage conditions before analysis: Samples that not analyzed immediately were refrigerated until analysis.

Vehicle:

yes

Remarks:

DMF

Test organisms (species):

Cyprinodon variegatus

Details on test organisms:

TEST ORGANISM
- Common name: Sheedshead Minnow
- Strain: Cyprinodon variegatus
- Source: Aquatic BioSystems, Inc., Fort Collins, Colorado

METHOD FOR PREPARATION AND COLLECTION OF FERTILIZED EGGS
Eggs were reported by the supplier to have been collected during natural spawning of conditioned adult fish which were introduced into spawning tanks less than 24 hours prior to the test initiation. Fertilized eggs were shipped to T.R. Wilbury Laboratories by overnight express delivery. Fertilization was confirmed at test initiation by direct visual observation with a microscope and the embryos were free of apparent disease, injuries, and abnormalities at the beginning of the test. At that time it was visually confirmed that the eggs were less than 24 hours post-fertilization. Identification of fish was verified at the end of the test using an appropriate taxonomic key.
POST-HATCH FEEDING: Beginning on day 5, fish were fed newly hatched Artemia salina nauplii (Argent Chemical Company, Redmond, Washington, lot number BS05) twice each day except during the final 24 hours of the test.

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

36 d

Test temperature:

30±1°C

pH:

6.9 - 7.1

Dissolved oxygen:

5.0 - 7.3 mg/L

Salinity:

15-17 ppt

Nominal and measured concentrations:

Nominal concentrations of Famoxadone Technical were 0 µg/L (control and solvent control), 3.0, 6.3, 13, 25, and 50 µg/L. Mean measured concentrations of Famoxadone were ND (not detected at or above the limit of quantitation of 0.960 µg/L; control and solvent control), 2.83, 5.58, 11.2, 22.4, and 43.5 µg/L.

Details on test conditions:

Eighty embryos were randomly and equally distributed among two replicates of each treatment using a random numbers table. Embryos were exposed in cages that consisted cylinders (8 cm high x 8 of glass cm diameter) that were closed at one end with 350 µm Nitex® screen. Two cages, each containing 20 embryos, .were suspended in each replicate test vessel. The cages were oscillated slowly by means of a rocker arm apparatus to assure an adequate flow of media around the embryos. Hatching was complete after day 4 of exposure. At day 4 of the exposure, hatched fish in all test vessels were thinned to 15 per replicate using a random numbers table and released from the exposure cages.

The test was performed in approximately 9 liter glass aquaria (approximately 15 cm in width, 30 cm in length, and 20 cm in height) that contained approximately 8 liters of test solution (water depth was ~17 cm). Test vessels were randomly arranged in a water bath during the 36 day test (a random numbers table was used to select the location of each vessel).

Duration:

36 d

Dose descriptor:

LOEC

Effect conc.:

11.2 µg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

other: most sensitive endpoint was the percent of live, normal fish at hatch

Duration:

36 d

Dose descriptor:

other: MATC

Effect conc.:

7.91 µg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

other:

Remarks:

most sensitive endpoint was the percent of live, normal fish at hatch

Duration:

36 d

Dose descriptor:

NOEC

Effect conc.:

5.58 µg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

other:

Remarks:

most sensitive endpoint was the percent of live, normal fish at hatch

Details on results:

No insoluble material was observed in any vessel during the test. Mean measured concentrations of Famoxadone were 86 to 94% of nominal concentrations and stable throughout the toxicity test.

There was at least 95 % hatch in the control and solvent control test vessels, the hatch in each control and solvent control chamber was less than 1.6 times the hatch in the other control chamber, and the number of live, normal control fish at 32 days post hatch was at least 87% in each control chamber. Control and solvent control fish had an average wet weight (blotted) of 176 and 183 mg, respectively, and an average total length of 21 mm at the end of the test. The relative standard deviation of the weights of surviving fish in the control test chambers was less than 40%. Maximum loading rate during the toxicity test was approximately 0.38 g/L at any time and 0.030 g/L/24 hours. Sublethal effects observed as fish lying on their sides and/or exhibiting lethargy were noted at 22.4 µg/L on days 4, 5, and 6 of the definitive test. These effects were not observed at any other time during the test. No other sublethal effects were noted at any other time or concentration.

Validity criteria fulfilled:

yes

Conclusions:

36-day NOEC = 5.58 µg/L
36-day LOEC = 11.2 µg/L
36-day MATC was 7.91 µg/L
The most sensitive measured biological endpoint was the percent live, normal fish at hatch.

Executive summary:

An early life stage toxicity of test Famoxadone Technical to the sheepshead minnow, Cyprinodon variegatus, was conducted according to U.S. EPA Pesticide Assessment Guideline Subdivision E, 72-4. The test was performed under flow-through, unaerated conditions with five concentrations of test substance, a solvent control (0.10 mL/L dimethylformamide), and a dilution water control at 30 ± 1°C. The dilution water was natural seawater collected from the Atlantic Ocean in Marblehead, Massachusetts, and diluted to a salinity of 15 to 17 parts per thousand with deionized water. Nominal concentrations of Famoxadone Technical were 0 µg/L (control and solvent control), 3.0, 6.3, 13, 25, and 50 µg/L. Mean measured concentrations of Famoxadone were 0, 2.83, 5.58, 11.2, 22.4, and 43.5 µg/L, and concentrations were stable throughout the test.

 

Embryos used in the test were less than 24 hours old and in good condition at the beginning of the test. Measured biological parameters were the time to hatch start and end, survival of embryos and juveniles, the number and percent of healthy embryos after 48 hours of exposure, the number and percent of healthy embryos hatched, length and wet weight of surviving fish, time to first feeding, and sublethal effects. There was at least 87% survival in the control and solvent control test vessels, control and solvent control fish had an average wet weight (blotted) of 176 and 183 mg, respectively, and an average total length of 21 mm at the end of the test.

Exposure of embryonic, larval, and juvenile sheepshead minnows to Famoxadone Technical resulted in a LOEC of 11.2 µg/L, a NOED of 5.58 µg/L and a MATC of 7.91 µg/L. The most sensitive measured biological endpoint was the percent of live, normal fish at hatch.

Reference 2

Endpoint:

fish life cycle toxicity

Adequacy of study:

supporting study

Study period:

2/8/2017 - 6/14/2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

Version / remarks:

2013

GLP compliance:

yes

Remarks:

The analytical verification of the test substance in the pre-exposure period was performed under non-GLP conditions.

Specific details on test material used for the study:

Purity: 98.2%
Batch: DPX-JE874-427

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 5 µg/L
Prior to the proposed test start, the flow through system was equilibrated and samples from all test vessels were taken for chemical analysis. This was performed concomitantly to ensure the right test concentrations and the correct adjustment of the dosing pump system. Samples were immediately transferred to the chemical analysis laboratory and measured.

If the test concentrations could not be confirmed, the dosing system was re-adjusted and after a further equilibration phase with at least one total exchange of test media, again samples from all test vessels were taken and the procedure was repeated. The analytical verification of the test substance in the pre-exposure period was performed under non-GLP conditions.

From each sample, an aliquot was taken and used for analytical measurement. After analysis, the samples were stored at ≤ -18 °C.

After confirmation of the correct test concentrations, the experimental phase was started by introducing the fertilized eggs, larvae or juveniles.

At the test start samples were taken in each vessel of the true control, transfer control, solvent control and the treatment vessels and also of the respective transfer vessel. At the end of pulse 1 all treatment vessels were sampled. Thereafter, samples were taken at start of the peak and at the end of each peak set. Three representative replicates of Set 3 (= treatment) were sampled alternately per peak event.

After pulsed applications, the specimens were transferred to larger vessels. Before introduction of the fish, all vessels were sampled and analysed to confirm absence of famoxadone. At the end of the study all transfer vessels were sampled again.

Vehicle:

yes

Remarks:

DMF

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: Oncorhynchus mykiss, Teleostei, Salmonidae
- Source: Forellenzucht Hirschquellen, Flugplatzstraße 48 - 52, 33758 Schloss Holte-Stukenbrock
Germany
METHOD FOR PREPARATION AND COLLECTION OF FERTILIZED EGGS
Fresh fertilised eggs were obtained. For study Set 1, the fish eggs were directly introduced into the aquaria. For study Sets 2 and 3, the fish eggs were bred under flow through conditions (for a description of study Sets see 4.3.2 Exposure procedure), until the fish reached the desired status. The fish eggs, newly hatched larvae and juveniles were randomly introduced into the exposure aquaria.
POST-HATCH FEEDING: In part III, newly hatched larvae did not receive food until the end of the sac fry stage as mentioned in the guideline. The feeding commenced at the time period of swimming up, which represents approximately day 40 to 50 dpf of fish age. The juveniles were fed at least 2 times daily with trout starter food. From approximately 60 dpf onwards, fish food was changed to fine pelleted trout food (at least 2 times daily).

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

9 d

Remarks on exposure duration:

Different life stages were exposed. A pulsed exposure scenario with a single concentration of nominal 5.0 μg/L contained a total number of 9 pulses with an exposure time of 24 hours per pulse. Time interval between treatment pulses was 7.2 hours

Hardness:

1.0-1.2 mmol/L

Test temperature:

9.3-11.4°C (Part I)
9.4-11.5°C (Part II)
9.8-11.0°C (Part III)

pH:

7.7-8.3 (Part I)
7.8-8.3 (Part II)
7.7-8.3 (Part III)

Dissolved oxygen:

Oxygen saturation:
88-108% (Part I)
85-106% (Part II)
82-104% (Part III)
:

Conductivity:

244-255 µS/cm

Nominal and measured concentrations:

Nominal test concentrations was 5 µg/L. Measured concentrations were 5.96 µg/L (Part I), 6.77 µg/L (Part II), and 5.52 µg/L (Part III).

Details on test conditions:

Study Part I: Fertilized eggs, start of exposure
Twenty randomly chosen fertilized eggs were placed in wide glass beakers. The beakers were placed on the bottom of each aquaria, to ensure full contact and exchange with the test medium. For every transfer, the beakers were taken out by using crucible tongs and carefully transferred. The overlaying test medium in the beaker was rinsed, thereby dryness of the legs was prevented.
At the end of the pulse exposure period, the embryos were transferred from the chamber into the main water body of the test vessel and were kept undisturbed until they reached day 90 of life, i.e. 90 dpf.

Study Part II: Newly hatched larvae, start of exposure
Twenty randomly chosen newly hatched larvae were placed into wide glass beakers. During the pulse exposure phase the larvae were kept in these chambers and were transferred within them. After the end of the pulse exposure period, the larvae were transferred out of the chambers into the main water body of the unexposed vessels. They were kept undisturbed until the end of the study period after reaching an age of 90 days pf.

Study Part III: Juvenile fish, start of exposure
Juvenile fish already swimming up and having an age of approximately 60 days were placed in controls and the treatment vessels. 20 fish were randomly chosen and introduced into each test vessel. For each transfer, the fish were taken out of the vessels using a net and were carefully transferred.
After the pulse exposure period, the fish were kept in dilution water and were undisturbed until they reached an age of 104 days.

Duration:

9 d

Dose descriptor:

NOEC

Effect conc.:

5.96 µg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

other: Part I (fertilized eggs): no statistically significant difference between the solvent control and treatment with the test item famoxadone was detected

Duration:

9 d

Dose descriptor:

LOEC

Effect conc.:

6.77 µg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

other: Part II (newly hatched larvae): weight and length of the fish at test end were significantly reduced in the treatment group

Duration:

9 d

Dose descriptor:

LOEC

Effect conc.:

5.52 µg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

other: Part III (juvenile fish): significant reduction of survival, length and weight

Validity criteria fulfilled:

yes

Conclusions:

In study Part I (fertilized eggs), no statistically significant difference between the solvent control and treatment with the test item famoxadone was detected. In study Part II (newly hatched larvae), weight and length of the fish at test end were significantly reduced in the treatment group, compared to the solvent control. In study Part III (juvenile fish), the statistical evaluation revealed a significant reduction of survival in the treatment group compared to solvent control. Also for both growth endpoints, length and weight, a significant reduction in the treatment group, compared to the solvent control was found.

Executive summary:

The study aimed at identifying potential adverse effects of famoxadone, during three different life stages of Rainbow Trout (Oncorhynchus mykiss). Fertilized eggs (study Part I), newly hatched larvae (study Part II) and juvenile fish (study Part III) were exposed to a pulsed exposure scenario with a pulse concentration of 5.0 μg famoxadone/L under flow-through conditions. The pulsed exposure scenario with a single concentration of nominal 5.0 μg famoxadone/L contained a total number of 9 pulses with an exposure time of 24 hours for each pulse. The time interval between treatment pulses was 7.2 hours.The endpoints, hatching rate, mortality, growth and behavioural abnormalities were recorded for each study part.

 

In study Part I (fertilized eggs), no statistically significant difference between the solvent control and treatment with the test item famoxadone was detected. In study Part II (newly hatched larvae), weight and length of the fish at test end were significantly reduced in the treatment group, compared to the solvent control. In study Part III (juvenile fish), the statistical evaluation revealed a significant reduction of survival in the treatment group compared to solvent control. Also for both growth endpoints, length and weight, a significant reduction in the treatment group, compared to the solvent control was found.

Reference 3

Endpoint:

fish life cycle toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10/7/1994 - 1/5/1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 72-4 (Fish Early Life-Stage and Aquatic Invertebrate Life-Cycle Studies)

Version / remarks:

1986

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

Version / remarks:

1990

GLP compliance:

yes

Specific details on test material used for the study:

Purity: 97.4%
Batch: DPX-JE874-221

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.102, 0.256, 0.640,1.60, 4.00, and 10.0 µg/L
- Sampling method: Samples were collected for quantitative analysis on days -1,0, 7, 14, 21,28, 35, 42, 47, 56, 63, 70, 77, 84, and 90 of the study. Day -1 values were not included in calculations of the mean, measured concentrations but were analyzed to confirm test solution concentrations prior to test start.
- Sample storage conditions before analysis: Samples were frozen immediately after collection, stored frozen, and then thawed and concentrated 100:1 by extraction with hexane prior to analysis.

Vehicle:

yes

Remarks:

DMF

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: Oncorhynchus mykiss
- Source: Mt. Lassen Trout Farms (Red Bluff, California)

METHOD FOR PREPARATION AND COLLECTION OF FERTILIZED EGGS
- Numbers of parental fish (i.e. of females used to provide required number of eggs): Eggs and sperm were received in separate plastic bags which were kept on ice (about 4°C) during shipping. Eggs and sperm were allowed to warm up to 9.7°C, were then mixed and allowed to sit for about 20 minutes.
- Method of collection of fertilised eggs: The embryos were then rinsed with dilution water to remove excess sperm and other debris, and were transferred to two 5-gallon tanks, each containing 10 L of cold (10°C) dilution water, set in a water bath (9.8°C) under darkness. Approximately 23 hours later, embryos were placed into embryo cups using random numbers to begin the test.

POST-HATCH FEEDING: On day 45, feeding was initiated; the fingerlings were fed newly-hatched brine shrimp (Artemia sp, Aquarium Products, Glen Burnie, MD) three times daily on weekdays, twice daily on weekends and holidays, and one time on day 45. The fingerlings were last fed on day 89, approximately 19 hours prior to test conclusion on the following day.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

90 d

Hardness:

79-83 mg/L as CaCO3

Test temperature:

10.4-11.2°C

pH:

7.0-7.6

Dissolved oxygen:

9.0-10.2 µg/L

Conductivity:

140-153 µmhos/cm

Nominal and measured concentrations:

Nominal test concentrations were 0.102, 0.256, 0.640,1.60, 4.00, and 10.0 µg/L. Mean, measured concentrations of the active ingredient were 0.11, 0.26, 0.62, 1.4, 4.1, and 9.8 µg/L.

Details on test conditions:

Embryo cups were inspected daily, and unfertilized eggs and damaged or fungus infected embryos were removed. The criteria for embryo death was opaque appearance. After hatching (completed on day 33 of the test) and until thinning, the alevins (larval fish with yolk-sacs) remained in the embryo cups in the DMF control and the 1.4 and 9.8 µg/L mean, measured test concentrations. Varying numbers of alevins were found outside the embryo cups and were free swimming within the "B" replicate test chamber of the following measured test concentrations: 0.26 and 0.62 µg/L from day 41 to 45, 0.11 µg/L on day 44 and 45, 4.1 µ/L on day 44, and water control from day 43 to 45. Therefore, statistical analysis of the first and last day of hatching and percent hatch were based on data from individual embryo cups on day 40. Since the alevins were found outside their individual embryo cups from the two embryo cups were pooled for each of the "A" and "B" replicate test chambers for analysis of larval survival abnormalities and first day to swim-up. On day 45, the surviving fingerlings were thinned (15 per replicate) using random
numbers and released into the appropriate test chamber replicate. The number of live fingerlings was determined daily by actual count.

A dilution water control, DMF control, and six test concentrations were used. Nominal test concentrations were 0.102, 0.256, 0.640,1.60, 4.00, and 10.0 µg/L. Concentration of DMF in all test solutions, with exception of the water control, was 0.1 mL/L. Test chambers were assigned to test concentrations using random numbers. Test solutions were prepared by diluting stock DPX-JE874-221 solutions in 1000 ml of well water in the mixing chambers of the diluter. All six stock solutions and DMF control were delivered via a Rainin Rabbit-Plus™ peristaltic pump. Test solutions in the mixing chambers were continuously stirred by a Teflon stir bar driven by a magnetic drive. Test solutions were delivered intermittently (once about every 10 minutes;
144 1-L volume additions every 24 hours) to test chambers from a Mount and В rungs proportional diluter constructed of glass and Tygon® tubing (for surfaces not exposed to test substance).

Test chambers were 21-L glass aquaria (41 [length] x 20.5 [width] x 26 [height] cm) split into two replicates, each holding approximately seven liters (10.5-L replicate test chamber volume; 16.5-cm liquid depth) and fitted with a screen mesh-covered overflow pipe. A recirculating water bath was used to maintain temperature in the test chambers at 10 ± 2°C, and test chambers were positioned in the water bath using random numbers. The volume of each replicate chamber was exchanged approximately ten times daily. No significant events occurred during the study that affected the flow rate. The occurrence of an electrical shutdown on day 47 minimally impacted diluter operation since a total of 136 volume additions (the targeted number of volume additions per day was 144) was delivered. Moreover, test solution samples taken on the same day showed recoveries of the active ingredient within 70 and 130% of targeted nominal values at all but the lowest test concentration. Two 212-mL screen mesh-bottom, glass, embryo cups (5.5-cm diameter) were suspended into each replicate: 20 embryos were placed into each embryo cup (total of 40 embryos per replicate and 80 embryos per test concentration). Emoryo cups were assigned to each replicate and embryos were assigned to embryo cups using random numbers. Embryo cups oscillated at one cycle per 80 seconds (2.5- to 6.0-cm water depth in embryo cup). Diluter operation was checked daily, and test solution concentrations were verified by chemical analysis immediately prior to beginning the test and weekly thereafter or at total mortality in a replicate. Loading in the "A" replicate of the water control at the end of the test was 0.1338 g fish per liter passing through the test chamber in 24 hours, based on the daily turnover rate of approximately ten test solution volumes. Test solutions were held between 10.4° and 11.2°C (mean = 10.7°C) and were unaerated. The embryos and alevins were kept in relative darkness until hatching was completed. On day 33, a 16-hour light (96.84 - 118.36 Lux) and an 8-hour dark photoperiod was used. Twenty-five minutes of transitional light (approximately 4.3 Lux) preceded and followed the beginning and end of the primary lighting.

Duration:

90 d

Dose descriptor:

LOEC

Effect conc.:

4.1 µg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

other: statistically significant differences in fingerling abnormalities (small size, dark coloration) and standard length at test end

Duration:

90 d

Dose descriptor:

other: MATC

Effect conc.:

2.4 µg/L

Nominal / measured:

meas. (arithm. mean)

Duration:

90 d

Dose descriptor:

NOEC

Effect conc.:

1.4 µg/L

Nominal / measured:

meas. (arithm. mean)

Details on results:

Nominal test concentrations were 0.102, 0.256, 0.640, 1.60, 4.00, and 10.0 µg/L. Mean, measured DPX-JE874 concentrations were 0.11, 0.26, 0.62, 1.4, 4.1, and 9.8 µg/L. The control solutions contained no detectable concentrations of the active ingredient except for one sample. On day 90, a peak approximately equal to the limit of quantitation was seen in a water control replicate. The observation was considered to be spurious since DPX-JE874 was not detected in the other water control replicate at this time point or in any other water and DMF control samples. Results of analyses for days 0 through 90 showed that recoveries of active ingredient in 129 out of the 156 test solution samples analyzed were between 70 and 130% of targeted nominal values. The number of results below 70% or above 130% of nominal was greatest at the lowest concentration and dropped to zero at the highest concentration. The week to- week variability in measured DPX-JE874 concentrations was largest at 0.11 and 0.26 µg/L, the two lowest concentrations tested. At 1.4 µg/L, the NOEC for the study, only two out of 28 analyzed samples were less than 70% of nominal.

Hatching success for the water and DMF control was 77.5 and 90.0%, respectively. The difference was marginally insignificant (p = 0.0523). Analysis using only the DMF control gave similar results as analysis using the combined controls. Larval survival from hatch to thinning was 100% in both controls. Fingerling survival from thinning to test end in the water and DMF control was 93.3 and 96.7%, respectively. No abnormal alevins were seen in either control at thinning. At the end of 90 days, one fingerling out of 29 was smaller than the others in the DMF control but all surviving fingerlings were normal in the water control.

Calculations were performed using mean, measured concentrations. EC50s for survival (or LC50s) from hatch to thinning and from thinning to test end were 6.7 (µg/L, with a 95% fiducial interval of 4.9 to 10 µg/L, and 4.6 |µg/L (the fiducial interval could not be calculated), respectively. EC50s for abnormalities from hatch to thinning and from thinning to test end were 8.6 µg/L, with a 95% fiducial interval of 5.6 to 25 (µg/L, and 7.7 µg/L, with a fiducial interval of 5.1 to 23 µg/L, respectively.

There were no statistically significant differences in the first and last day of hatching. Percent hatch was significantly reduced at 9.8 µg/L when compared against the combined controls or DMF control only. Larval survival and abnormalities from hatch to thinning were significantly different at 9.8 µg/L. All surviving alevins at this concentration were pale and smaller than alevins at the other test concentrations.

Other abnormalities (pale-colored larva, larvae lying on bottom of vessel with yolk sac still present, pale-colored larva with curved tail, larva with two heads, one embryo sac and one tail, larva lying on bottom of vessel and gasping for air with yolk sac still present) were not toxicologically significant since they were random in occurrence and affected 2.9% or less of the remaining live fish at each concentration.

First day of swim-up was delayed at the two highest concentrations; the differences were statistically significant only at 9.8 µg/L. Fingerling survival was significantly reduced at 9.8 µg/L: all fish that survived to day 45 at 9.8 µg/L were dead by day 47. At the next highest concentration, 4.1 µg/L, fingerling survival at test end was 80%; this difference was not statistically significant but was considered to be toxicologically significant. The incidence of abnormal fingerlings (small size, dark coloration) at 4.1 µg/L was significantly higher than in the controls. Standard length of surviving fingerlings at 4.1 µg/L was also significantly different from the controls at test end; however, the differences in wet weight were not significant.

Validity criteria fulfilled:

yes

Conclusions:

The NOEC (no observable effect concentration), MATC (maximum acceptable toxicant concentration), and LOEC (lowest observed effect concentration) were 1.4, 2.4, and 4.1 µg/L, based on statistically significant differences in fingerling abnormalities (small size, dark coloration) and standard length at test end.

Executive summary:

Rainbow trout, Oncorhynchus mykiss, embryos, alevins and fingerlings were exposed to DPX-JE874-221 in a flow-through, 90-day chronic test. The test was conducted according to OECD guideline 210. Nominal test concentrations were 0.102, 0.256, 0.640,1.60, 4.00, and 10.0 µg/L. Mean, measured concentrations of the active ingredient were 0.11, 0.26, 0.62, 1.4, 4.1, and 9.8 µg/L. Calculations were performed using mean, measured concentrations.

 

There were no statistically significant differences in the first and last day of hatching. Percent hatch, and larval survival and abnormalities from hatch to thinning were significantly different from the controls at 9.8 µg/L First day of swim-up was delayed, and fingerling survival from thinning to the end of the test was reduced at 9.8 and 4.1 µg/L; however, only the differences at 9.8 µg/L were statistically significant. The incidence of abnormal fingerlings at 4.1 µg/L was significantly different from the controls. Standard length of surviving fingerlings at test end was also significantly different at 4.1 µg/L; the differences in wet weight were not significant.

In summary, the NOEC (no observable effect concentration), MATC (maximum acceptable toxicant concentration), and LOEC (lowest observed effect concentration) were 1.4, 2.4, and 4.1 µg/L, based on statistically significant differences in fingerling abnormalities (small size, dark coloration) and standard length at test end. While differences were observed in time to swim-up and fingerling survival, they were not statistically significant.

Description of key information

Freshwater

9-day NOEC (Rainbow trout, Oncorhynchus mykiss) = 5.96 µg/L, OECD 210, Reliability = 1

90-day NOEC (Rainbow trout, Oncorhynchus mykiss) = 1.4 µg/L, OECD 210 and OPP 72-4, Reliability = 1

Saltwater

36-day NOEC (sheepshead minnow, Cyprinodon variegatus) = 5.58 µg/L, OPP 72-4, Reliability = 2

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

NOEC

Remarks:

90-day

Effect concentration:

1.4 µg/L

Marine water fish

Marine water fish

Dose descriptor:

NOEC

Remarks:

36-day

Effect concentration:

5.58 µg/L

Additional information

Famoxadone was tested in 2 tests in the freshwater species, Rainbow trout.  The 9-day NOEC was 5.96 µg/L one test whereas the 90-day NOEC was 1.4 µg/L in a second test.  In saltwater species (sheepshead minnow), the 36-day NOEC was 5.58 µg/L.